SPP 2171 Summer School: Dynamic Wetting of Flexible, Adaptive, and Switchable Substrates

Volatile binary mixtures on polymer brushes

Nicht eingeplant

20m

University of Münster

Poster

Sprecher

Jan Diekmann

Beschreibung

We present a mesoscopic thin-film model in gradient dynamics form for binary liquid mixtures on brush-covered substrates incorporating volatility in a narrow gap. Thereby, we expand models established in [1, 4–6] by incorporating two substances present in each of three bulk phases - liquid, brush and gas. We discuss the different contributions to the free energy, thereby employing Flory-Huggins theory of mixing for the condensed phases and assuming ideal gases for the vapor phase. Interface energies are modeled as linear interpolations of known limiting cases. The resulting six-field model is then analyzed with numerical time simulations showing results with a focus on lateral concentration gradients, notably at the contact line. Limitations and possible expansions are discussed and briefly outlined.
[1] S. Hartmann, C. Diddens, M. Jalaal, and U. Thiele. Journal of Fluid Mechanics, 960, 2023. doi: 10.1017/jfm.2023.176.
[2] S. Hartmann, J. Diekmann, D. Greve, and U. Thiele. 2023. doi: 10.48550/ARXIV.2311.07307.
[3] S. Schubotz, Q. A. Besford, S. Nazari, P. Uhlmann, E. Bittrich, J.-U. Sommer, and G. K. Auernhammer. Langmuir, 39, 2023. doi: 10.1021/acs.langmuir.2c03009.
[4] L. A. Smook, G. C. R. van Eck, and S. de Beer. Macromolecules, 53, 2020. doi: 10.1021/acs.macromol.0c02228.
[5] U. Thiele and S. Hartmann. The European Physical Journal Special Topics, 229, 2020. doi: 10.1140/epjst/e2020-900231-2.
[6] Özlem Kap, S. Hartmann, H. Hoek, S. de Beer, I. Siretanu, U. Thiele, and F. Mugele. The Journal of Chemical Physics, 158, 2023. doi: 10.1063/5.0146779.